1. Field of the Invention
The invention relates to the field of system maintenance, and in particular, to physical labeling of a system after a field service/upgrade.
2. Background Information
In electronic systems, such as the typical desktop personal computer systems, it is known to store certain basic system information in non-volatile memory which is commonly referred to as SRAM (static random access memory) or CMOS, because it is generally memory formed with complimentary metal oxide semiconductor technology. Of course, this type of memory is only xe2x80x9cnon-volatilexe2x80x9d as long as a voltage is applied to it, either from the computer system power supply or from an on-board battery when the computer system is powered down. The information stored in CMOS includes hardware information, for example, system memory size, hard disk drive type and other peripheral device information. This information is sometimes manually entered by the computer manufacturer at the time the system is configured, or by a user when the system is upgraded by adding a new component. The information stored in CMOS memory is used by the computer""s basic input output system (BIOS), which is a set of routines generally stored as firmware in read only memory (ROM) disposed on the computer system mother board, to establish parameters for communication between the computer system hardware, including peripheral devices, and the operating system software. Some BIOS versions have an automatic detect feature to detect a device""s parameters. For example, when a new hard drive is added to the system, the user can manually configure the required parameters to be stored in CMOS memory, or the user can have the BIOS automatically detect the drive type, number of cylinders, heads, etc., of the new hard drive, for storage in CMOS. Further, some recent computer systems use what is called a xe2x80x9cplug-and-playxe2x80x9d (PnP) BIOS, in which the BIOS automatically detects the installation of a new device having PnP compatibility, and attempts to configure necessary input/output drivers and parameters for the device. However, in this known method, the BIOS and operating system only know the device by its logical address, and not its actual physical location. That is, it is not readily apparent to the user or service personnel from the BIOS or operating system, to which card slot on the mother board a device is physically connected. In small desktop computer systems this is not generally a concern since the number of peripherals such systems can accommodate is usually relatively small making their location relatively easy.
Typical medium to large size computer systems include at least one backplane, which is essentially a connecting board having integrated wiring and bus slots or other connectors, for interconnecting various computer system circuits designed to connect to the backplane. The backplanes connect circuits such as special purpose input-output and/or control circuits, for use in interfacing peripheral devices, for example, such as direct access storage devices (DASD""s, e.g., hard disk drives), to the rest of the computer system. These circuits are generally disposed on modules or cards which have standard connectors for plug-in to backplane at bus sockets or slots, to thereby connect with the rest of the computer system by way of the backplane. This allows for easy removal, servicing, upgrading and replacement by service personnel and/or experienced users.
In large and complex electrical systems, such as large computer systems, there is a need for the operating system (OS) to be able to correlate a physical location, or xe2x80x98bayxe2x80x99, within a computer chassis with a device or subsystem at that location. This correlation is needed in order to be able to readily service or upgrade the system.
If a peripheral device, for example a DASD, is operating at a substandard level, the computer operating system should detect and indicate such to a user of the system to alert service personnel. In the case of a failed hard drive, the system might report xe2x80x9cerror reading drive Xxe2x80x9d (where xe2x80x9cXxe2x80x9d is the logical drive name) on the display console of the system, for example. In small desk-top computer systems, when such an error is reported, it is generally relatively easy for service personnel to locate the hard drive in question, and the related interface card device, since there is only one enclosure and typically only one or two hard drives provided.
With larger and more complex computer systems, such as servers for small and large office environments, typically more peripheral devices, hard drives, and associated backplanes and interface cards are used, and they may be disposed in separate chassis enclosures, also called xe2x80x9cframesxe2x80x9d or xe2x80x9ctowers,xe2x80x9d and xe2x80x9cdrawersxe2x80x9d (self-contained entities which can be slid in and out of a chassis enclosure as a unit) forming an interconnected multi-tower system. In such systems, locating a device in need of servicing may be more difficult and/or time consuming, unless the operating system can indicate the location of the device in question by tower, backplane, and card-slot, for example. One computer system that is sometimes configured as a multi-tower computer system is the IBM AS/400 (IBM and AS/400 are trademarks of International Business Machines Corporation, all rights are reserved). The towers of this computer system in its multi-tower configuration are interconnected by at least one host system bus. However, even in a single tower system there may be a significant number of backplanes, each with a number of slots, making physically locating a particular xe2x80x9clogicalxe2x80x9d device difficult and/or time consuming without first establishing a logical to physical location correlation.
The correlation for service has been accomplished in the past using a combination of a physical label at the xe2x80x98bayxe2x80x99 location within the computer enclosure which service personnel can refer to, and some xe2x80x98boot-codexe2x80x99 within the operation system. The xe2x80x98boot-codexe2x80x99 is generally loaded at the time of system manufacture and contains information about how the chassis was built, i.e., configured, at the time of manufacture.
However, a problem with this method is that changes to subsystem structures in the field are not reliable. The maintenance personnel adding/subtracting or changing chassis configuration in the field are relied on to input the newly affixed labeling information and structure into the operating system.
Typically, reconfiguration of a computer primarily consists of replacing hardware devices, such as DASD""s (direct access storage devicesxe2x80x94hard disk drives) or PCI (peripheral component interconnect) cards. In some cases, subsystems are also replaced during a system upgrade. For instance, a processor and memory xe2x80x98cartridgexe2x80x99 might be upgraded with a faster processor and more memory. However, additional information on how the physical box labeling layout might change as a result was often neglected.
At the present time, some manufacturers are conducting an initiative to xe2x80x98standardizexe2x80x99 the physical xe2x80x98outsidexe2x80x99 dimensions of server boxes. For example, INTEL has an initiative called SHV for Standard High Volume servers. With standardization of the box volume, there comes a need to be able to re-label the enclosure components during a subsystem upgrade. Upgrading is desirable at the xe2x80x98Serverxe2x80x99 box level, since these boxes are usually very expensive and, for inventory and other reasons, many users have a desire to maintain the Serial Number of the overall chassis while replacing the xe2x80x98gutsxe2x80x99 of the machine to obtain better performance.
A system power control network (SPCN) is known from U.S. Pat. No. 5,117,430 and copending application Ser. No. 08/912,561, filed Aug. 18,1997, entitled xe2x80x9cFAIL-SAFE COMMUNICATIONS NETWORK FOR USE IN SYSTEM POWER CONTROLxe2x80x9d attorney docket number RO997-083-IBM-101. The SPCN communications network is a low volume serial network used to monitor power conditions at a plurality of nodes in a computer system, in particular, the IBM AS/400 (IBM and AS/400 are registered trademarks of International Business Machines Corporation). The nodes typically include microprocessors which monitor the status of, and make occasional adjustments to, the power conditions at the respective nodes.
It is further known to store vital product data (VPD) for correlating the physical locations of system components with their corresponding logical addresses in a computer system from the copending patent application Ser. No. 08/971,687, filed Nov. 17, 1997, entitled xe2x80x9cMETHOD AND APPARATUS FOR CORRELATING COMPUTER SYSTEM DEVICE PHYSICAL LOCATION WITH LOGICAL ADDRESSxe2x80x9d attorney docket number RO997-154-IBM-108, assigned to the same assignee as the present application. As described therein, memory, e.g., non-volatile memory, is provided on a backplane and written with VPD information, such as the type of backplane, manufacture date, backplane serial number, type of slots on the backplane, etc., and this information is retained for use by the operating system if and when needed for service action, upgrades, or for on-line configuration management and order process.
Further, the VPD information may advantageously be accessed, for example, using an SPCN such as those which are disclosed in the above-mentioned U.S. Pat. 5,117,430 and in the other related application Ser. No. 08/912,561.
There is a need for a reliable means of sensing changes in chassis subsystems and updating software images with appropriate labeling information, through the operating system.
It is, therefore, a principle object of this invention to provide a method and apparatus for reassigning slot labels based on vital product data (VPD).
It is another object of the invention to provide a method and apparatus that solves the above mentioned problems so that an operating system (OS) is able to correlate a physical location, or xe2x80x98bayxe2x80x99, within a computer chassis with a device or subsystem at that location in order to be able to readily service or upgrade the system.
These and other objects of the present invention are accomplished by the method and apparatus disclosed herein.
According to an aspect of the invention, in an electrical system having subsystems, and which stores configuration labeling information therein, a method includes detecting subsystem configuration, and updating the stored configuration labeling information based on the detecting. Service personnel can access the stored configuration labeling information to use in affixing labels at appropriate locations in the electrical system.
According to an aspect of the invention, the subsystems have vital product data (VPD) storage associated therewith, and the detecting includes reading vital product data corresponding to each subsystem from the respective associated vital product data storage.
According to another aspect of the invention, the detecting is performed at predetermined times during operation of the electrical system. These predetermined times may include at initialization of the electrical system, during an electrical system service action (concurrent maintenance), and at regularly scheduled time intervals during the electrical system operation, for example.
According to another aspect of the invention, the electrical system is a computer system which includes a system power control network, and the reading is accomplished by the system power control network.
According to another aspect of the invention, configuration labeling information may be stored in the electrical system at the time of assembly of the electrical system with subsystems, subsystem configuration changes being detected at some time after assembly, and labeling information being updated.
According to another aspect of the invention, labeling information for a new subsystem may be derived from vital product data memory associated with the subsystem, from a distribution diskette provided by the manufacturer of the subsystem, or from an Internet web site associated with the subsystem manufacturer, for example.
According to another aspect of the invention, a method of maintaining system labeling in an electrical system having a plurality of subsystems, includes applying power to the subsystems, accessing a table having hardwired addresses and subsystem identification information for the subsystems, and querying the subsystems at the respective hardwired addresses for subsystem identification information. The subsystem information gathered in the querying is compared to the subsystem identification information stored in the table in order to detect subsystem changes, and make a determination if a subsystem change requires a change in system labeling. Maintenance personnel are signaled that a change in labeling is required if so determined.
According another aspect of the invention, there is provided an apparatus for maintaining slot labels.
These and other aspects of the invention will become apparent from the detailed description set forth below.